docs: def update_contact(self, um_from_user, um_to_user, message):
          """ Get or update a contacts information """
          contact, created = self.get_or_create(um_from_user,
                                                um_to_user,
                                                message)
  
          # If the contact already existed, update the message
          if not created:
              contact.latest_message = message
              contact.save()
          return contact